The present invention is directed in general to communication systems, and more particularly, to a digital electronic communication management and information switching system which operates under dispersed microprocessor control to manage the interconnection, usage, record keeping and maintenance of various types of conventional and specialized voice, data and facsimile terminals.
During the past decade, the emphasis in electronic system design has been on centralized control using computers of various size, degree of sophistication and complexity. However, with the implementation and use of such systems over a period of time, concern has been expressed over various inherent disadvantages of the centralized processing system, including lack of flexibility, obsolescence, and serious maintenance problems which have literally rendered such systems totally unusable in response to individual device failures within the system. On the one hand, complaints have been heard that a particular system was not capable of handling certain business office problems, having been designed for general use in an effort to provide a universal product. On the other hand, even for those fortunate enough to obtain a system suitable for their specific needs, the problem of obsolescence presented itself only too quickly, especially in conjunction with systems that could not be expanded. Finally, the problem of down-time in central processing systems presented the ultimate frustration since malfunction in the system generally resulted in the entire system becoming disabled, therey rendering it totally useless until repairs could be made. This interference with business was more than just an inconvenience to the businessman; it represented an unacceptable limitation on his ability to adequately serve his customers and clients and resulted in a serious waste of manpower and other resources.
In an effort to overcome the above-mentioned disadvantages in centralized processing systems, designers began to turn to modular concepts of system design, and with the significant advances in microprocessor development which brought a drastic reduction in the cost of microprocessor manufacture, distributed processing within a system began to replace the centralized processing of prior years.
In additon, new types of systems began to be developed. In the communication fields, the emphasis has shifted toward digital systems. Thus, in the telephone industry, digital central office and private branch exchange systems have been developed and made available for use by the public. At the same time, new data communication systems involving the transmission of all types of data and information in digital form have been developed. Systems have been developed for word processing as well as data processing and electronic message functions in an effort to provide a more complete scope of services for the standard business office or large corporation. These systems include not only electronic private branch exchanges, but also shared resource word processing and data processing systems; however, there has been a tendency to design such systems independently of one another, i.e., word processing systems, data processing systems and telephone exchanges which are self-contained and designed specifically for those respective functions. Thus, the business office typically may have a number of local networks and other computer resources providing data, text, and messages all flowing through or residing in respective systems in the form of a high volume of digitized information that must be accessed, sent, processed, managed and manipulated, as well as verbal information that needs to be communicated throughout the system. Such a situation calls for a communication hub or switching system into which the information can flow, be it data, text, voice or messages and be switched to its destination while simultaneously recording information on each transaction.